John Reid has announced a cull of health targets but new NHS star ratings have put the credibility of the government's foundation hospitals scheme under the spotlight.

Several trusts have seen their performance slip considerably over just 12 months, casting doubt on the accuracy of the data being used to assess performance.

Three of the new elite foundation trusts saw their ratings fall from the maximum three stars to two over allegedly poor financial management.

A further two trusts went from no stars a year ago to three stars no, while one fell from three stars to none.

To qualify for foundation status, which grants more freedom from Whitehall and extra financial liberties, hospital trusts must first achieve a three star rating.

Academics have questions the veracity of the assessment system because of the big swings.

"How can anyone have confidence in a system of measurement where hospitals oscillate from one end of the table to the other over a 12-month period?" asked professor of health management at Durham University, David Hunter.

The Conservatives moved immediately to call for the end of the star system.

"Star ratings do not give an accurate reflection of a hospital's performance. They are extremely misleading for patients, who should rightly assume that a three star hospital must be better than a trust with one or no stars; but this is not the case," shadow health secretary Andrew Lansley said.

"Out of the 15 general acute trusts with the worst MRSA ranking, 14 achieved a tick in the box for cleanliness in their star ratings."

The Conservative frontbencher also pointed to the loss of status for trusts which passed the eligibility criteria to become foundation trusts and said that one third of the trusts applying for foundation status from this October have performed worse this year than last.

"Ask the staff and management of those trusts which have lost stars this year and most will tell you that the quality of clinical care they offer is the same or even better than last year," Lansley added.

"Star ratings are arbitrary and perverse and there is no place for them in a patient centred NHS."

Targets

Meanwhile, the health secretary announced on Wednesday that the number of NHS targets is to be cut from 62 to 20, while those that have been achieved by April next year will have to be maintained.

"The hard work of NHS staff, coupled with these targets, has delivered results - falling waiting times and massive reductions in mortality rates of the biggest killers, heart disease and cancer," Reid said.

"Seven years ago, almost 120,000 people were waiting over nine months for treatment. Now just a handful wait that long.

"Targets have led to 19,000 more doctors and 67,500 more nurses since 1997 as well as the biggest hospital building programme in the history of the NHS.

"Patients now expect - and are receiving - faster, better treatment. The next stage is to build on these achievements by further raising the quality of care."

But he insisted that the government was not turning its back on targets.

"Improved performance means that the new standards I'm announcing today can reflect this shift towards improving the quality of care," he said.

"Reduction in national targets does not mean a let-up in ensuring high performance.

"Targets will still have a role to play - for example, we're committed to cutting the entire waiting time to a maximum of 18 weeks by 2008."